Also interested in battery recommendations. I know they were around earlier in the thread, now, though, people will ave tried out some of them. It would be great to hear impressions/comparisons.
I've done extensive battery tests, as it really has a big effect on the sound. I have samsung, kinps, anker, gold and pisen. Samsung is easily the best, no point comparing to the rest. But a major problem is getting a genuine one. I have 10 samsung batteries, 6 of them are fake, and I can tell fake from genuine purely by the sound, and that is the only way! Both the fake and genuine batteries look 100% identical physically!
The most interesting part is that among genuine samsung batteries there are three different types-, Cell made in Japan, Cell made in Korea, Cell made in China, and their sound quality is also in that order, best to worse. (yes I have all three)
[size=12.8000001907349px]The difference between a good battery and a bad battery is internal impedance (lower is better), the two big factors this effects sonically are extension on both ends (bass, treble) and frequency balance, from a transparency point of view.[/size]
I literally can hear my Japan battery extending further in bass and higher in treble than the Korean battery, lets call it one notch more. The balance of frequencies is perfect, nothing boosted, everything remarkably tight and extended. Low internal impedance = extended, balanced, [size=12.7272720336914px]transparent.[/size]
Comparing to the Korean battery, the extension audibly does not extend as deep or as high, The higher internal impedance also has another effect, it bumps up the mid bass and lower treble, causing a more V shaped sound, and the bump is not a clean bump, as in the mid bass becomes boomier
and louder, same as the treble, it gets splashier, as well as louder. And I'm not confusing the bumped mid bass and treble for less extention, there is literally a higher cut off for bass and a lower cut off for treble
as well as the bumps. The mids also lose some clarity, sounding more congested. Basically the combination of all these effects is what I'm calling a lowering of transparency, as the sound is no longer true to the music file or even the rest of the DX90 hardware.
Also remember all these effects are only "1 notch" worse than the Japan battery (its about 5% to me), so its not as bad as I'm making it sound, but for an audiophile like me
its bad enough to make me happy to spend even $150 on a genuine Japan battery (not that I have, but its worth that much to me), its seriously worth it to me, as its the only way to get the DX90's true untainted sound, I find the DX90's pure balanced sound to be a beautiful thing. The reason I have 10 samsung batteries is I'm still hunting for more Japan batteries! I have two at the moment
I'm still hunting for more, that's how much I love them. Without them the DX90 is no longer a reference DAP imo, for critical listening they are a must have.
So yeah, don't get me wrong, the genuine Korean version is still a notch better than the genuine Chinese one, which is a notch better than the anker, pisen types, which are better than the samsung fakes.
Also remember when I say a notch lower, its a notch lower in all the sound components mentioned previously, there is no "sound signature" differences between batteries, just internal impedance difference which has the previous mentioned effects. You could say one battery sounds crap and the other one sounds good though
It amazes me the difference the battery can make! Makes me truly wonder how good are the batteries in other daps, especially since you can't swap for other batteries in most daps! I feel the Japan samsung battery is essentially the epitome of battery quality, which is why I'm trying to collect at least 4 of them, so I can be using my DX90 long into the future, I just don't trust the batteries in those other daps! Its DX90 for me all the way, plus DX90 plus Japan battery does equal faultless sound in my opinion.
Also interesting to note is that all these sound changes also carry through to the DX90's Line out! So using a lesser battery is not going to be remedied by using an external amp. And the japan battery provides beautifully extended and balanced sound out of the line out. I
FYI I have bat ears, also fyi I'm not the only person to have come to the conclusion that Japan battery sounds best, there aren't many of us, but I suspect that mostly has to do with the extreme scarcity of the genuine Japan batteries, and also the complete mess with fake batteries, I have several fake batteries that say Cell made in Japan, but clearly don't sound like they were!
